Prior to The Color Purple, Wells worked as trainee assistant director on Clint Eastwood's drama Breezy (1973), as second assistant director on the comedy Let's Do It Again (1975), the comedy Silent Movie (1976, with second unit director Max Kleven), the sport drama The Greatest (1977), and the crime drama Rolling Thunder (1977), and as first assistant director on the action film Convoy (1978), episodes of Hotel (1983), and the television drama International Airport (1985). Between 1982 and 1986, Wells also worked as first and second assistant director, second unit director and director of seven episodes on the comedy series The Love Boat. He also directed episodes of Hotel (1985, starring Michael Spound, Theodore Bikel, and Robert DoQui) and Glitter (1985, with David Birney and Melinda Culea).

Further credits as first assistant director includes episodes of The Colbys (1987), In the Heat of the Night (1988), Columbo (1989), Wild Oats (1994), Ellen (1995), Pearl (1996), and See Jayne Run (2007). Film credits include the crime drama Cop (1988), the horror comedy Rockula (1990), the sport comedy White Men Can't Jump (1992, with Robert J. Metoyer), the science fiction comedy The Meteor Man (1993), the television movie The Johnny Chronicles (2002), and the television movie Night Life (2008). Beside directing, Wells was credited as unit production manager on the television series Pearl (1996), The Larry Sanders Show (1997-1998), and Moesha (1999).

Between 2001 and 2009, Wells worked as first assistant director on 71 episodes of the comedy series Scrubs. He also worked as unit production manager on several episodes and directed three episodes in 2004, 2006, and 2007. In the first season episode "My Way or the Highway" (2002), he had a cameo role as a patient. The episode also featured Trek alumni Ken Jenkins. In 2007, he was the first assistant director and executive producer on the short horror comedy The Fifth.

More recently, Wells worked as first assistant director on the comedy series Cougar Town (2009-2010).